Drill into viewHierarchyState

This library is great!

```
10-11 11:53:13.179 D/TooLargeTool(21791): MainActivity.onSaveInstanceState wrote: Bundle@161550193 contains 7 keys and measures 821.2 KB when serialized as a Parcel
10-11 11:53:13.179 D/TooLargeTool(21791): * android:sessionId = 0.1 KB
10-11 11:53:13.179 D/TooLargeTool(21791): * com.google.app_measurement.screen_service = 0.2 KB
10-11 11:53:13.179 D/TooLargeTool(21791): * map_state = 0.2 KB
10-11 11:53:13.179 D/TooLargeTool(21791): * android:fragments = 0.8 KB
10-11 11:53:13.179 D/TooLargeTool(21791): * @android:autofillResetNeeded = 0.1 KB
10-11 11:53:13.179 D/TooLargeTool(21791): * android:lastAutofillId = 0.1 KB
10-11 11:53:13.179 D/TooLargeTool(21791): * android:viewHierarchyState = 819.7 KB
```

I'd like to figure out what part of the viewHierarchyState is taking up so much room. Any thoughts on how to best allow drilling-down in a situation like this? I could specify keys that I want to be drilled-down into when I call `TooLargeTool.startLogging(this)`? Or we could automatically drill down into the keys above a certain size? Happy to put together a PR if you give me some guidance on what approach(es) you'd be ok with.